<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>水平线标签</title>
    <style>
        span{
            width: 400px;
            height: 150px;
            border-bottom: 1px solid red;
        }
    </style>
</head>
<body>
    <div>ssssssss</div>
    <hr>
    <span>ssssssssssdssdss</span>

</body>
</html>